Multilayer Body

ABSTRACT

A multilayer body includes a transparent first layer. In the transparent first layer, a multiplicity of microlenses arranged in accordance with a microlens grid are impressed in a first region. Furthermore, the multilayer body includes a second layer, which is arranged below the first layer and in a fixed position with respect to the first layer and has a multiplicity of microimages arranged in accordance with a microimage grid and in each case in an at least regional overlap with one of the microlenses of the microlens grid for the purpose of generating a first optically variable information item. The grid pitches of the microimage grid and of the microlens grid in each case in at least one spatial direction are less than 300 μm.

The invention relates to a multilayer body which can be used, inparticular, as a security element for protecting security documents, inparticular banknotes, as a security document, e.g. banknotes, valuabledocuments or ID documents, for product protection or for packagingapplications.

It is known to use Moiré effects as security features for protectingsecurity documents. Thus, by way of example, EP 1 238 373 B describes amethod in which a characteristic Moiré intensity profile can be obtainedby placing a main grid and a base grid one above another. The “hiddeninformation” arising as a result of the main and base grids being placedone above another is in this case coded into the design of theindividual grid elements of the base and main grids. By displacing thebase and main grids relative to one another, an optically varyingimpression arises here for the human observer.

The invention is based on the object, then, of specifying an improvedmultilayer body which conveys an optically variable impression.

This object is achieved by a multilayer body comprising a transparentfirst layer, in which a multiplicity of microlenses arranged inaccordance with a microlens grid are impressed in a first region, andcomprising a second layer, which is arranged below the first layer andin a fixed position with respect to the first layer and has amultiplicity of microimages arranged in accordance with a microimagegrid and in each case in an at least regional overlap with one of themicrolenses and the microlens grid for the purpose of generating a firstoptically variable information item, wherein the grid pitches of themicroimage grid and of the microlens grid in each case in at least onespatial direction are less than 300 μm. By virtue of an arrangement ofthis type, when the multilayer body is tilted, for the human observerupon viewing the multilayer body from the front side, i.e. on the partof that side of the first layer which faces away from the second layer,interesting, in particular two-dimensional or three-dimensional,optically variable effects with or without a depth effect arise.

Advantageous configurations of the invention are designated in thedependent claims.

In accordance with one preferred embodiment of the invention, therespective grid pitch of the microlens grid in a first spatial directionis greater by at least 50%, in particular by more than 100%, than therespective dimension of the respective microlens in the first spatialdirection. In this case, grid pitch of the microlens grid is understoodto be the respective microlens distance between the respective microlensand its adjacent microlens which is determined by the spacing-apart ofthe area centroids of the microlenses. Thus, the microlens grid spans acoordinate system having a first coordinate axis and a second coordinateaxis, which is preferably at right angles with respect thereto. In thedirection of the first coordinate axis and/or in the direction of thesecond coordinate axis, the microlenses of the microlens grid thensucceed one another, wherein the area centroids of the microlensespreferably lie on a line oriented parallel to one of said coordinateaxes and preferably parallel to the first spatial direction. Thedimensions of the respective microlens in the first spatial direction isthe distance between the base points of the respective microlens, whicharise as a result of the intersection of a straight line, oriented inthe direction of the first spatial direction and passing through thearea centroid of the respective microlens, with the outer boundary lineof the respective microlens.

It has been found that in the case of such a procedure, the layerthickness of the multilayer body that is necessary for generating theoptical variable effect can be significantly reduced. Thus, the focallength of the microlens influences firstly the layer thickness of thefirst layer that is necessary for the impression of the microlenses, andalso the spacing-apart of the second layer from that surface of thefirst layer which faces away from the second layer. If the focal lengthis increased, then although the layer thickness of the first layer thatis necessary for impression decreases, the distance between the basepoints of the microlenses and the second layer, which preferably lies inthe range of the focal length of the microlenses, correspondinglyincreases. By means of the measures described above, although the lightintensity of the first optically variable information item is reducedsomewhat, the layer thickness of the multilayer body can besignificantly reduced despite the effects described above.

Furthermore, it has proved to be advantageous to use microlenses whosemaximum structure height is at least 35%, in particular at least 50%, ofthe dimension of the respective microlens in the first spatialdirection. Maximum structure height of the respective microlens isunderstood to be the maximum elevation of the microlens above the basepoint plane of the microlens that is spanned by the base points of themicrolens.

In accordance with a further preferred exemplary embodiment of theinvention, the respective dimension of the microimages in the firstspatial direction is chosen such that it is more than 50%, in particularmore than 100%, of the dimension of the respectively adjacentmicrolenses in the first spatial direction. It has surprisingly beenfound that, in the case of such a dimension of the microimages, theoptically variable appearance can be further improved, in particular theangular range at which an optically variable effect becomes visibleduring tilting can be further improved.

Preferably, the microimages have a smallest dimension of less than 300μm, preferably of less than 100 μm. Smallest dimension means that thissmallest dimension is taken to be the compressed, smallest extent of themicroimages, which, in the non-compressed extent, can be considerablygreater than the smallest dimension. Smallest dimension of a zone, of animage or of a microimage is thus understood to be the dimension selectedfrom length and width which is the smaller. In the case of more complexshapings, in order to determine the width and length, a correspondingvirtual rectangular is determined, which is chosen such that the complexshaping is arranged within the rectangle and as many as possible of theboundary lines of the more complex shaping touch the edges of therectangle.

In accordance with a further preferred exemplary embodiment of theinvention, the microimages are not applied on a planar surface, butrather on a curved surface. This affords the advantage that therespective microimage is arranged over rather a large angular rangeapproximately in the range of the focal length of the microlens and,consequently, the optical appearance of the multilayer body is improved,in particular the contrast sharpness at larger tilting angles issignificantly improved.

In this case, the curvature is impressed into that layer of themultilayer body which is arranged above or below the microimage layer.As viewed from the direction of the microlens grid, the curvature hasits deepest point in the central region of the respective microimage.The curvature preferably extends over the entire region of themicroimage. However, it is also possible not to arrange the entiremicroimage in the region of the curvature. The deepest point of thecurvature has, with respect to this highest point (edge region of thecurvature) a height difference which is preferably in the range ofbetween 5 and 25% of the width of the respective microimage.

Preferably, in order to produce the curvature in the region of therespective microimage, a surface structure is impressed into a layerarranged above or below the microimage layer, onto which the microimagelayer is then applied. Said surface structure preferably has a shapingsimilar to the respective microlens, that is to say a shaping which, ifappropriate, is mirrored relative to the shaping of the respectivemicrolens 21 at the plane spanned by the longitudinal and transversedirections of the multilayer body and is distorted in said plane by adistortion factor f. Mirroring at the plane should be providedparticularly when the surface structure is impressed into a layerarranged below the microimage layer, such that the condition mentionedabove is met. If the microlens is therefore a spherical microlens, thenthe curvature has a sphere-surface-shaped shaping. If the microlensesare spherical cylindrical lenses, then the curvature has the shaping ofa cylinder surface. In this case, the distortion factor f is preferablychosen so as to comply with the above-specified height differencesbetween the edge and the deepest point of the curvature with respect tothe size of the microimage.

In accordance with a further preferred exemplary embodiment of theinvention, the multilayer body comprises a carrier substrate having alayer thickness of more than 6 μm, in particular more than 12 μm. Thecarrier substrate is then embodied in transparent fashion in a secondregion or has a window-shaped perforation in the second region, whereinthe second region preferably covers the first region over the full area.The first layer is then arranged on the front side of the carriersubstrate and the second layer is arranged on the rear side of thecarrier substrate. This procedure affords a number of advantages: thus,firstly the security of the security element is further increased byvirtue of the fact that the first layer and the second layer have to beapplied to a common carrier substrate by means of two application stepsto be performed with register accuracy with respect to one another.Register fluctuations in the application processes, in particular evenslight rotations relative to one another of the elements applied to thefront and rear sides of the carrier substrate by means of theapplication processes, become immediately visible as a result of theMoiré effects that occur, such that a copy of such a multilayer body andthe removal of the film elements from a multilayer body and applicationto a further multilayer body by a counterfeiter—in particular on accountof the achievable register accuracies for this of approximately 0.5mm—are possible only with great difficulty and a counterfeit is directlyrecognizable. Furthermore, the layer thickness of the layers to beapplied on the carrier substrate can be significantly reduced as aresult, since the carrier substrate itself acts as an optical spacerlayer between the first and second layers. As a result, the hapticproperties of a valuable document, for example of a banknote, areinfluenced only insignificantly by the implementation of the layersgenerating the first optically variable information, and the resistanceof the valuable document to the mechanical loads that occur during useis also further improved. Preferably—as already mentioned above—themultilayer body is in this case a valuable document and the carriersubstrate constitutes the carrier substrate of the valuable document,for example the banknote substrate. The carrier substrate thusconstitutes, for example, a banknote's carrier substrate which consistsof paper, plastic, or a sequence, e.g. a laminate of paper and plasticlayers, and which preferably has a layer thickness of 30 to 200 μm.

Preferably, in this case the multilayer body has in the first region athird layer, which is arranged below the second layer and which, whenthe multilayer body is viewed from the rear side, generates a secondoptically variable information item, which is not visible to the humanobserver when viewing the front side of the multilayer body and differsfrom the first optically variable information item. In this case, alayer which is opaque to the human observer at least in reflected-lightviewing is preferably also arranged between the second and third layers,and enables reliable optical separation of the first and secondoptically variable information items. This measure further improvessecurity in respect of copies and provides succinct security featuresthat are easily recognizable for the observer.

Further advantages arise from the fact that in the first layer and/or inthe second layer in a region adjoining the first region, preferablyenclosing the first region, even further security elements, preferablyembodied in opaque fashion, are formed, which interact intransmitted-light viewing and, for example in transmitted-light viewing,complement one another to form an optically variable information item.Furthermore, it is advantageous for printing layers applied to the frontor rear side of the carrier substrate likewise to contain such securityelements, which, together with such security elements provided in thefirst, second or third layer, complement one another intransmitted-light viewing to form an information item that can berecognized in transmitted-light viewing. This further increases thesecurity against counterfeiting.

In accordance with a further preferred exemplary embodiment of theinvention, the multilayer body has a translucent layer arranged betweenthe first layer and the second layer. Further interesting opticallyvariable effects can be obtained by virtue of this measure. Thus, it isthereby possible for the first optically variable effect to be visibleas a watermark only upon transmitted-light viewing. In reflected light,however, the first optically variable effect is not visible. In thisembodiment, the microimages are preferably formed in each case by one ora plurality of image regions arranged in front of a background region,wherein the one or the plurality of image regions is or are embodied inopaque fashion and the background region is embodied in transparentfashion, or vice versa. In this case, the opaque image regions or opaquebackground regions can be formed, for example, from opaque lacquerlayers, opaque metal layers. The opaque regions and/or the transparentregions can comprise UV-active, IR-active materials or magneticmaterials, which can then have optical and/or machine-readableadditional functions. Furthermore, in this embodiment, the multilayerbody preferably comprises a carrier substrate which is embodied intransparent fashion in the first region or has a window-shapedperforation in the first region. The multilayer body thus preferablyconsists, in the background regions, of the translucent layer, of atleast one opaque layer and optionally of one or a plurality oftransparent layers and, in the image regions, of the translucent layerand one or a plurality of transparent layers, or vice versa.

The translucent layer preferably has scattering properties. Preferably,the translucent layer has a transmissivity of between 1% and 50%, morepreferably of between 5% and 30%, averaged over the wavelength rangevisible to the human observer. Furthermore, the translucent layerpreferably has the following volume scattering properties: scattering ofa proportion of between 5% and 50% of the incident light at scatteringangles of >5° on average over the wavelength range visible to the humanobserver.

In accordance with a further preferred exemplary embodiment of theinvention, the second layer has in the first region at least one firstzone, in which the microimages are provided, and has at least one secondzone, in which optically active surface structures for generating athird optically variable information item are provided, said thirdoptically variable information item differing from the first opticallyvariable information item. In this case, the optically active surfacestructures are preferably diffractive surface structures which generatefor example in the second zones a hologram or a Kinegram®(Kinegram®=optically variable effect with color change effects and/orimage change effects in the case of a changing viewing angle and/orchanging illumination conditions) as third optically variableinformation item. In this case, it is possible for the microlenses thento be provided only in the first zones, but not in the second zones.Furthermore, it is also possible for the microlenses to be provided bothin the first and in the second zones and thus for the microlens grid tocover both the first and the second zones. In this case, it isparticularly advantageous when the first layer, in the at least onesecond zone, is provided with a lacquer layer, in particular isoverprinted with a lacquer layer, the refractive index of which differsfrom the refractive index of the first layer by less than 0.3. Thisadditional lacquer layer extinguishes the optical effect of themicrolenses in the at least one second zone, such that the microlensescan no longer influence the optical appearance of the optically activesurface structure arranged in the at least one second zone. Thisprocedure further improves the security of the multilayer body againstcounterfeiting and copying. Errors in the register-accurate arrangementof the first and second layers with respect to one another lead directlyto the disturbance of the first and third optically variable informationitems or a boundary region between first and third optically variableinformation items becomes visible, which exhibits distinct disturbingeffects that are immediately discernible to the human observer.Therefore, even tiny register deviations between first and second layersbecome discernible to the human observer.

Preferably, the at least one second zone has a smallest dimension ofmore than 300 μm and is shaped in patterned fashion for generating afourth information item. Thus, the at least one second zone is shapedfor example in the form of a letter, a number, a symbol or a pictorialrepresentation which represents the fourth information item.

Furthermore, it is advantageous if the first region is subdivided into amultiplicity of first and second zones, and the first and second zonesare arranged in accordance with a regular grid having a grid pitch ofless than 300 μm in at least one spatial direction. As a result, it ispossible to make the first and third optically variable informationitems visible to the human observer in one and the same surface regionof the multilayer body and thus to obtain distinctly recognizable,abrupt changes in the optical appearance in this region. Furthermore, inan embodiment of this type, both the first and the third opticallyvariable information items are disturbed very distinctly even in thecase of small register fluctuations, such that even tiny registerfluctuations become directly discernible even to the unpracticedobserver and a counterfeit or copy of the multilayer body is thus madesignificantly more difficult.

In accordance with one preferred exemplary embodiment of the invention,the microimages are formed in each case by one or a plurality of imageregions arranged in front of a background region or surrounded. Themicroimages consist for example in each case of a motif, for example inthe form of a letter, a number, a text, a symbol or an image, whichforms the one or the plurality of image regions and which is visible infront of a background region, i.e. is visible as a result of thecontrast against the background region. In this case, the motif can besurrounded by a background region adjoining the boundary line of themotif or else comprise partial motifs or cutouts which are separated bythe background region or filled by the latter. In this case, it is alsopossible for the color, the reflection properties and/or the absorptionproperties of the second layer to be varied within the image region.

As already mentioned above, it is possible for the one or the pluralityof image regions of the microimages to be opaque and the backgroundregion or the background regions to be transparent, or vice versa.Furthermore, it is also possible for the one or the plurality of imageregions and the background region to have different transmission orreflection properties. It is furthermore advantageous if the imageregions and the background region have different polarizationproperties, e.g. different linear polarization or different circularpolarization or else different elliptical polarization states.

The second layer can consist of an individual layer or of a plurality ofpartial layers, in particular has a metallic layer, a colored lacquerlayer and/or a photoresist layer which is provided in the first regionin the image regions and is not provided in the background region, orvice versa. In this case, the photoresist layer preferably consists of apositive or negative photoresist, which more preferably can also becolored with a dye or pigment.

Furthermore, it is advantageous if the image regions and/or thebackground regions are covered with an optically variable element, inparticular the image regions, on the one hand, and the backgroundregions, on the other hand, are covered with different opticallyvariable elements. The optically variable elements could be formed, forexample, by optically active surface reliefs, in particular bydiffraction structures, for example diffraction structures such asholograms or a Kinegram®, anisotropic or isotropic matt structures,moth-eye structures, asymmetrical or symmetrical grating structures,linear grating structures, cross grating structures, hexagonal gratingstructures, zeroth-order diffraction structures or combinations of suchdiffraction structures. In particular, it can be advantageous to usediffraction structures which are covered with a preferably metallicreflection layer and absorb a large portion of the incident light, inparticular linear grating structures, cross grating structures, orhexagonal grating structures having grating periods in the range of 100nm to 500 nm, particularly preferably in the range of 200 nm to 400 nm,and structure depths in the range of 50 nm to 2000 nm, particularlypreferably in the range of 200 nm to 1000 nm. It is furthermoreadvantageous if the optically variable elements are formed by thin-filmlayer elements which have an optical layer thickness of λ/2 or λ/4, forλ in the wavelength range of visible light, and exhibit viewingangle-dependent color shift effects, or is formed by a liquid crystallayer which exhibits different polarization properties in differentregions or likewise exhibits a viewing angle-dependent color shifteffect. It is furthermore advantageous if the optically variableelements comprise UV-active, IR-active materials, in particular pigmentsor dyes or magnetic materials, in particular particles or laminae.Advantageously, the second layer thus also has a replication lacquerlayer having a surface relief impressed into the surface of thereplication lacquer layer, wherein—as explained above—the surface reliefimpressed in the image regions, on the one hand, and in the backgroundregions, on the other hand, is different.

In accordance with one preferred exemplary embodiment of the invention,the microlens grid is arranged in a manner rotated at an angle of 45°with respect to the longitudinal axis of the multilayer body. It hasbeen found that particularly interesting optical effects can thereby begenerated particularly when a one-dimensional microlens grid is used.If, by way of example, a one-dimensional microlens grid in which thefocal point lines—preferably oriented parallel to one another—of themicrolenses are arranged at an angle of 45° with respect to thelongitudinal axis of the multilayer body is thus used, then apredetermined movement effect that can proceed at any angle from 0 to360°, that is to say in any desired direction, is manifested upon thetilting of the multilayer body both about an approximately horizontalaxis and about an approximately vertical axis. Furthermore, a movementalong a nonlinear path, for example along a bent curve, can also beeffected. Longitudinal axis of the multilayer body is understood in thiscase to be the coordinate axis oriented in the direction of the lengthof the multilayer body.

Furthermore, it is preferred here for the multilayer body to have arectangular, in particular strip- or tape-shaped shaping.

In this case, it is possible for the first region, in which themicrolenses are provided, to cover the entire multilayer body or tocover a region over the entire length of the multilayer body or else tocover only a partial region of the multilayer body. Thus, it ispossible, for example, that alongside the first region even furtherregions, not covered by the microlenses, are provided on the multilayerbody, with other, preferably optically variable security elements beingprovided in said regions. However, these other, preferably opticallyvariable security elements can also be provided wholly or onlyregionally in the first region and in this case covered completely oronly regionally by the microlenses. Despite the covering with themicrolenses, other security elements can be perceptible and/or readablesufficiently for their effect or functionality, preferably opticallyand/or in machine-readable fashion.

In accordance with one preferred exemplary embodiment of the invention,the microlens grid and/or the microimage grid are/is a two-dimensionalmicrolens grid and/or microimage grid. In this case, the microlens gridand/or microimage grid span(s) a coordinate system having two coordinateaxes preferably at right angles to one another, wherein the microlensesand/or microimages succeed one another both in a first spatialdirection, in particular in the direction of one coordinate axis, and ina second spatial direction, in particular in the direction of the othercoordinate axis, with a respective grid pitch of between 5 μm and 150μm. In this case, the spacing-apart of adjacent microimages and/ormicrolenses is preferably determined by the spacing-apart of the areacentroids of the microlenses and/or microimages and preferablycorresponds to the respective grid pitch.

However, it is furthermore also possible for the microlens grid and/orthe microimage grid to be a one-dimensional microlens grid and/ormicroimage grid, in which two or more microlenses and/or microimagessucceed one another in one spatial direction with a respective gridpitch of between 5 μm and 300 μm.

In this case, the microimage grid and/or the microlens grid can be aregular grid having constant grid pitches, but also an irregular gridhaving varying grid pitches. Furthermore, it is also possible for thecoordinate systems spanned by the microlens grid and/or the microimagegrid to be geometrically transformed and thus for the coordinate axesnot to have the form of a straight line, but rather to be formed forexample in the shape of a wavy line or in circular fashion.

Preferably, the grid pitches of the microimage grid and microlens griddiffer from one another in each case for adjacent microimages andmicrolenses by less than 10%, in particular differ from one another bybetween 0.5 and 5%. In a configuration of this type, when identicalmicroimages are used, a Moiré magnification effect is brought about,that is to say that the first optically variable information itemvisible at a specific viewing angle corresponds to a magnifiedrepresentation of the (identical) microimages. However, even upon theuse of different microimages, which leads to the generation of morecomplex movement and transformation effects during the tilting of themultilayer body, this measure has proved to be advantageous.

It has furthermore proved to be worthwhile for the microimage grid andthe microlens grid to be arranged in a manner rotated by between 0.05°and 5° relative to one another, that is to say for the axes of themutually assigned coordinate axes of the coordinate system spanned bythe microimage grid and the microlens grid to form such an angle.

In accordance with one preferred exemplary embodiment of the invention,in the first region, the grid pitch of the microlens grid, the gridpitch of the microimage grid and/or the rotation of the microimage gridand of the microlens grid relative to one another are/is variedcontinuously in accordance with a parameter variation function in atleast one spatial direction. As a result, the magnification, reductionand transformation effects already mentioned above can be obtainedduring tilting.

Furthermore, it is advantageous if the microimage grid has in the firstregion at least two microimages which differ from one another. It isparticularly advantageous in this case if, in the first region, the formand/or the color of the microimages change(s) continuously in accordancewith a transformation function and, by way of example, movement effectscombined with magnification, reduction and transformation effects arethus brought about during the tilting of the multilayer body.

In accordance with a further preferred embodiment, in a first partialregion of the first region, the grid pitch of the microlens grid, thegrid pitch of the microimage grid and/or the rotation of the microlensgrid relative to the microimage grid are/is chosen such that theseparameters differ relative to the corresponding parameters in a secondpartial region of the first region. This has the effect that theoptically variable appearance in the first and second partial regionsdiffers from one another and the security against counterfeiting is thusimproved further.

The invention is explained by way of example below on the basis of anumber of exemplary embodiments with the aid of the accompanyingdrawings.

FIG. 1a shows a schematic sectional illustration of a multilayer body.

FIG. 1b shows a schematic plan view of a multilayer body.

FIG. 1c shows a schematic plan view of a multilayer body.

FIG. 1d shows an illustration for elucidating the functional principleof the multilayer body according to FIG. 1 c.

FIG. 1e shows a schematic plan view of a multilayer body.

FIG. 1f shows a schematic sectional illustration of an excerpt from amultilayer body.

FIG. 2 shows a schematic sectional illustration of the multilayer body.

FIG. 3 shows a schematic sectional illustration of a multilayer body.

FIG. 4 shows a schematic sectional illustration of a multilayer body.

FIG. 5 shows a schematic sectional illustration of a multilayer body.

FIG. 6 shows a schematic sectional illustration of a multilayer body.

FIG. 7 shows a schematic sectional illustration of a multilayer body.

FIG. 8 shows a schematic sectional illustration of a multilayer body.

FIG. 9 shows a schematic plan view of a multilayer body.

FIG. 1a shows a multilayer body 1 comprising a carrier substrate 10 anda film element applied on the carrier substrate, comprising an adhesivelayer 11, a decorative layer 12 and a transparent layer 13.

The carrier substrate 10 is preferably a paper substrate having a layerthickness of between 10 μm and 200 μm. If the multilayer body 1 is apackaging, then the carrier substrate can also be a (thick) cardboard orplastic substrate. However, it is also possible for the carriersubstrate 10 to be a substrate comprising one or a plurality of layers.The carrier substrate 10 preferably forms the carrier substrate of avaluable document, preferably of a banknote, and is thus, for example,optionally also printed with one or a plurality of layers on the frontside and/or on the rear side.

The film element comprising the layers 11, 12 and 13 is applied in theform of a patch or strip onto the carrier substrate 10. Said filmelement is thus, for example, a security thread or security strip, inparticular a window security thread or window security strip. However,it is also possible for the film element to cover the entire region ofthe carrier substrate 10 over the whole area. The film elementcomprising the layers 11, 12 and 13 is preferably applied as a transferlayer of a transfer film, in particular of a hot embossing film, ontothe substrate 10. However, it is also possible for the film element tobe embodied as a laminating film or as a security thread and to beapplied as such onto the carrier substrate 10 or to be introduced intothe carrier substrate 10.

The layer 11 is an adhesive layer having a layer thickness of between0.5 and 10 μm, preferably between 1 and 5 μm.

The decorative layer 12 is a layer having a multiplicity of microimages22 arranged in accordance with a microimage grid. The decorative layer12 thus consists, for example, of a structured, partially provided metallayer, in particular a metal layer having a layer thickness of 10 nm to5000 nm, which is shaped regionally in patterned fashion in order toform the microimages 22. In this case, the microimages 22 in each caseshow a motif formed by the contrast between one or a plurality of imageregions and one or a plurality of background regions 23 which exhibit adifferent optical appearance. Thus, in the configuration of thedecorative layer 12, as explained above, as a partial metal layer, byway of example, the metal of the metal layer is provided in the imageregions and not provided in the background regions 23, such that themicroimages 22 are manifested by the contrast between image regions andbackground regions 23. If the background regions are embodied intransparent or translucent fashion, for example by means of atransparent or translucent lacquer, the adhesive layer 11 is visiblethrough the background regions 23, said adhesive layer thereby servingas a contrasting background plane with respect to the image regions. Inthis case, it has proved to be advantageous to color the adhesive layer11 with colored pigments and/or dyes in order thus also to be able tomake the background regions 23 colored. Highly contrasting motifscomposed of, for example, metallic image regions and colored backgroundregions can thus be obtained. It is likewise possible to color theadhesive layer 11 alternatively or additionally with UV-active orIR-active pigments and/or dyes in order to be able to vary the contrasteffect between image regions and background regions 23 depending on theillumination condition.

Furthermore, it is also possible for the microimages 22 to be formed notonly by the decorative layer 12 but by a decorative layer printeddirectly on the carrier substrate 10 and/or by the superimposition ofthe decorative layer 12 with such a layer applied directly to thecarrier substrate 10. It is thus possible, for example, to print onfeatures which have a small phase variation with respect to the grid ofthe microlens grid. Furthermore, by way of example, an offset printingcan have a grid of background colors and image colors which has afrequency spread, whereas the lens grid has a constant frequency.

Instead of an offset printing, it is also possible here to use adifferent printing method, for example a gravure printing method, ascreen printing method, a pad printing method, an intaglio printingmethod or else an inkjet printing method.

Furthermore, it is also possible for the layer 12 to be formed by acolored lacquer layer or a colored photoresist layer or to consist of aplurality of (colored) lacquer layers, photoresist layers and/or metallayers which bring about a different optical appearance of thedecorative layer 12 in the image regions and background regions and thusform the microimages 22 in the decorative layer 12. Furthermore, it ispossible for the decorative layer to have a replication lacquer layer,in which an optically active surface relief is impressed. In this case,the optical contrast between image regions and background regions can bebrought about by virtue of the fact that the surface reliefs areimpressed either in the image regions or in the background regions or,in the image regions and in the background regions, different surfacereliefs are impressed into the replication lacquer layer. Thereplication lacquer layers and, in particular, the surfaces of thereplication lacquer layers into the which the respective surface reliefis impressed are provided with a reflection-increasing layer, forexample an HRI layer or a metallic layer, preferably composed ofaluminum, silver, copper, gold, chromium or an alloy comprising suchmetals. In this case, the decorative layer 12 thus has a replicationlacquer layer having an impressed surface relief and a reflection layer,which is preferably arranged below the replication lacquer layer. Inthis case, the optically active surface relief used is preferably adiffractive relief structure having a spatial frequency of more than 300lines/mm, preferably of 500 to 4500 lines/mm. The diffractive reliefstructure is preferably a computer-generated diffraction grating, forexample a dot matrix or e-beam hologram, wherein said diffractiongrating differs for example in terms of azimuth angle, spatialfrequency, profile form or relief depth in the image regions andbackground regions. Furthermore, it is also possible for the surfacerelief used to be an anisotropic or isotropic matt structure, moth-eyestructures, asymmetrical or symmetrical grating structures, lineargrating structures, cross grating structures, hexagonal gratingstructures, zeroth-order diffraction structures or combinations of suchdiffraction structures.

Furthermore, it is also possible for the decorative layer 11 tocomprise, in addition to or instead of the abovementioned layer, athin-film layer system for producing viewing angle-dependent color shifteffects, a liquid crystal layer or a layer comprising optically activepigments, for example UV pigments, liquid crystal pigments orinterference layer pigments. This layer, too, is preferably structuredsuch that it is provided either in the background regions or in theimage regions and thus brings about a contrast between image regions andbackground regions. Furthermore, it is also possible for the microimagesto have a color profile or different brightness values in the region ofan image region and the corresponding layers of the decorative layercorrespond are configured in order to correspondingly realize thisbrightness or color profile.

The microimages 22 are arranged—as already mentioned above—in accordancewith a one- or two-dimensional microimage grid, wherein the grid pitchof the microimage grid, that is to say the respective spacing-apart ofadjacent microimages 22, can be constant or else can vary. FIG. 1adepicts by way of example a grid pitch 42 of the microimage grid whichis determined by the microimage distance between the adjacentmicroimages 22 shown in FIG. 1a , that is to say the spacing-apart ofthe area centroids thereof with respect to one another.

The layer 13 consists of a material transparent to the human observerand preferably has a layer thickness of between 5 and 150 μm.Microlenses 21 are impressed into that surface of the layer 13 whichfaces away from the layer 12, as is indicated in FIG. 1a . Themicrolenses can be spherical microlenses, but also any other lens forms,in particular also cylindrical lenses. In this case, the cylindricallenses can be embodied spherically, aspherically or as diffractivelenses having any desired phase functions. In the simplest case, thefocal length of the lenses is determined here by their radius ofcurvature. The focal length of the microlenses is preferably chosen heresuch that the spacing-apart 46 of the microimages 22 from themicrolenses 21 is approximately in the range of the focal length of themicrolenses 21.

The relief depth, that is to say the distance between the highest andthe deepest points of the microlenses, is in this case preferablybetween 2 and 50 μm. The microlenses 21 can be introduced into thesurface of the layer 13 for example by means of an embossing tool, forexample by means of a mechanically acting embossing roller or anembossing stamp or by means of laser ablation. In this case, thetransparent layer 13 consists for example of a lacquer layer, of aplastic film, for example a film composed of PET (polyethyleneterephthalate), PEN (polyethylene naphthalate), or BOPP (biaxiallyoriented polypropylene) or of a plurality of layer plies, for example areplication lacquer layer and a transparent carrier film, for example aPET film, arranged below the latter. The impression of the microlensesinto the transparent layer 13 is in this case preferably effected bymeans of UV replication, that is to say by impressing the microlensstructure into a soft, not yet or only slightly cured replicationlacquer layer and subsequently curing the replication lacquer layerusing high-energy radiation, preferably UV radiation. However, it isalso possible that, in order to produce the microlenses 21, a lacquer isapplied to a transparent layer and is correspondingly provided with asurface corresponding to the microlens grid for example by means of ashaping tool or a physical process. Furthermore, it is also possible forthe microlenses 21 to be diffractive lenses.

Furthermore, it is also possible for even further transparent layers tobe provided in the multilayer body 1 between the layers 12 and 13, orelse for even further layers to be provided between the layer 11 and thelayer 12 or above the layer 13 in the multilayer body 1.

The microlenses 21 are arranged—as already explained above—in accordancewith a one- or two-dimensional lens grid, wherein the grid pitch of thelens grid can be constant or else can vary locally. Thus, FIG. 1 showsby way of example a grid pitch 41 corresponding to the microlensdistance between the adjacent microlenses shown in FIG. 1, that is tosay the spacing-apart of the area centroid thereof.

The spacing-apart 46 of the microlenses 21 from the microimages 22 ispreferably approximately in the range of the focal length of themicrolenses 21 and preferably deviates by not more than 10% from thefocal length of the microlenses 21.

The grid pitch of the microlens grid along the sectional line of thesection shown in FIG. 1 in this case is preferably between 5 and 300 μmand the grid pitch of the microimage grid in the direction of thesectional line is preferably between 5 and 300 μm. With regard to theshaping of the microimages 22, the configuration of the grid pitch ofthe microimage grid and microlens grid and the mutual orientation of themicrolens grid and microimage grid, reference is made to the previousexplanations.

Preferably, the microlenses 21 are arranged in accordance with aone-dimensional lens grid, as will be explained below by way of examplewith reference to the figures in FIG. 1b to 1 e.

Thus, FIG. 1b shows a plan view of an excerpt from the layer 13, whereinthe focal point lines of the microlenses 21 shaped in the form ofcylindrical lenses is indicated by lines in FIG. 1b . The microlenses 21are arranged in accordance with a one-dimensional microlens grid whichspans a coordinate system having the axes 50 and 51. The axis 50 of thecoordinate system is oriented parallel to the transverse axis of themultilayer body 1 and parallel to the focal point lines of themicrolenses 21 and the coordinate axis 51 is oriented perpendicular tothe coordinate axis 50. In this case, the microlenses 21 preferably havea length of more than 1 mm and the distance between adjacent microlenses21, the grid pitch 41, is less than 300 μm, preferably between 10 and200 μm. In the embodiment in accordance with FIG. 1b , the area centroidlines of the microimages 22 are preferably oriented substantiallyparallel or parallel to the coordinate axis 50 and the grid pitches ofthe microimage grid and of the microlens grid differ from one another,in particular by between 0.5 and 5%.

A further preferred exemplary embodiment will now be explained withreference to the figures in FIG. 1c and FIG. 1 d.

FIG. 1c shows a plan view of the layer 3, wherein—as in FIG. 1b —thefocal point lines of the microlenses 21 are identified by correspondinglines. Here, too, the microlenses 21 are formed by cylindrical lensesarranged in accordance with a one-dimensional microlens grid having agrid pitch 41 of between 10 μm and 300 μm, here 35 μm. The focal lengthof the microlenses is between 10 μm and 500 μm. As shown in FIG. 1d ,the focal point lines of the microlenses 21 are in this case rotated atan angle of 45° relative to the longitudinal axis of the multilayer body1 and are arranged substantially parallel to one another. In this case,the coordinate axis 51 illustrates the longitudinal direction of themultilayer body 1 and the coordinate axis 50 the transverse direction ofthe multilayer body 1, which is preferably a strip-shaped orthread-shaped security element. As explained in FIG. 1b , themicroimages 22 are arranged in accordance with a microimage grid,which—as described above—is arranged in a manner rotated relative to themicrolens grid (in particular is rotated by 45°) or, as described above,differs therefrom in terms of the grid pitch. This results in theoptical appearance 60 illustrated in FIG. 1d , in the case of whichoptical appearance foreground elements 61 describe a left-right movementupon the tilting of the multilayer body 1 into the horizontal axis and aleft-right movement upon the tilting of the multilayer body 1 about thevertical axis.

In the exemplary embodiment according to FIG. 1d , the multilayer body 1has, by way of example, a length of 100 mm and a width of 10 mm, that isto say a longitudinal dimension of 100 mm and transverse dimension of 10mm.

A further embodiment is illustrated by FIG. 1e . FIG. 1e likewise showsa plan view of the layer 13, wherein the focal point lines of themicrolenses 21 are likewise indicated here by lines. In this case, themicrolenses 21 are formed by cylindrical lenses which are arrangedconcentrically with respect to one another and which each have acircular shaping and are arranged in a manner spaced apart from oneanother in a grid pitch 41—as indicated in FIG. 1d . Furthermore, it isalso possible for the microlenses 21 to be arranged in accordance with ageometrically transformed one-dimensional microlens grid and thus, byway of example, for the focal point lines of the microlenses in theplane spanned by the coordinate axes 50 and 51 in each case to have awavy-line shaping.

A further exemplary embodiment is illustrated with reference to FIG. 1f. FIG. 1f shows an excerpt from the multilayer body 1 with a microlens21 and an assigned microimage 22. The microlens 21 is a cylindrical lenshaving a radius 47 and a maximum structure height 44. In the exemplaryembodiment according to FIG. 1f , the microimages 22—in contrast to whatis shown in FIG. 1a —are not arranged in a planar plane, but rather arearranged on a surface of the layer 13 which is curved in the region ofthe respective microimage 22. For this purpose, a surface structure isreplicated into the layer 13 both into the top side and into theunderside, wherein the surface structures provided in the region of themicroimages 22 preferably has a lens-type shaping—as has beenillustrated in figure if. As already explained above, the microstructureimpressed into the layer 13 in the region of the microimages 22 has asimilar shaping to the microlens 21 and thus forms a curvature in theform of a cutout of a cylindrical surface, as is illustrated in FIG. 1f.

In the case present here, in which the microlens 21 is embodied as aspherical cylindrical lens having a radius 47, the followingapproximately holds true:

$\frac{1}{x_{i}} = {\frac{1}{3r} + \frac{0.074}{r}}$

In this case, r is the radius of the microlens 21 and x_(i) is theposition of the image with respect to the normal to the surface of thelayer 13, that is to say corresponds to the dimension 46. For a radiusr=50 μm, this results in a parallax focus of 150 μm and a value of122.75 μm for the outermost image edge, that is to say a deviation of18%. The curvature for the microimage 22 is accordingly to be chosensuch that the deepest location of the microimage 22 is at a distance of150 μm from the top side facing away from the microimage, that is to saythat the dimension 46 is 150 μm, and that in the edge region of theimage the microimage is arranged at a distance of 122.75 μm from the topside layer 13.

FIG. 2 shows a multilayer body 2, which is improved and modifiedrelative to the multilayer body 1 in the manner described below:

The multilayer body 2 comprises the carrier substrate 10 and the filmelement comprising the layers 11, 12 and 13. The layer 13 is embodiedlike the layer 13 according to FIG. 1a to figure if with the differencethat the microlenses 21 in the region 31, unlike in the case of theembodiment according to FIG. 1, do not directly succeed one another,rather that “flat” regions are provided between the microlenses 21,which regions are not part of a microlens and do not contribute anythingto the deflection function of the microlenses 21. As illustrated in FIG.2, the lenses have, in the direction of the sectional line of thesection illustrated in FIG. 2, a dimension 43 which is smaller than therespective grid pitch of the microlens grid along the sectional line byat least 30%, in particular by more than 50%, that is to say that thedimension 43 is ≤0.5 grid pitch 41. Furthermore, the microlenses 21 havea maximum structure height, that is to say dimension 44, which is atleast 25%, in particular at least 50%, of the dimension 43 of themicrolenses. This configuration of the microlenses makes it possible tocorrespondingly reduce the layer thickness of the layer 13 and—asillustrated in FIG. 2—to make the layer thickness of the multilayer body2 significantly smaller than the layer thickness of the multilayer body1. As already mentioned above with regard to FIG. 1a , the distancebetween the base point plane of the microlenses 21 and the decorativelayer 12 is in this case chosen approximately (deviation ±10%) such thatit corresponds to the focal length of the microlenses 21. Since themicrolenses 21, on the other hand, cover a significantly smallerproportion of the area of the region 31, the maximum structure height ofthe microlenses 21 also correspondingly decreases upon the reduction ofthe focal length of the microlenses 21, such that a particularly thinconfiguration of the multilayer body 2 can be obtained by means of thesetwo effects.

The decorative layer 12 is embodied like the decorative layer 12according to FIG. 1a to FIG. 1f , wherein FIG. 2 shows an embodiment ofthe decorative layer 12 in which the decorative layer consists of atransparent replication lacquer layer 122 and a whole-area metal layer121, wherein, in the regions forming the image regions of themicroimages 22, a diffractive relief structure 123 is impressed into thesurface of the replication lacquer layer 122 and such a relief structureis not impressed into the background regions 23, that is to say thatthese regions are embodied as mirror regions. It is also worthmentioning here, moreover, that in the embodiment according to FIG. 2the dimension 45 of the microimages 21 in a first spatial direction,here in the direction of the sectional line of the section shown in FIG.2, is more than 50%, in particular more than 100%, of the dimension 43of respectively adjacent microlenses 21 in the first spatial direction.The advantages already set out above are obtained as a result.

In the case of the exemplary embodiment shown in FIG. 2, the dimension43 is preferably between 5 μm and 100 μm, the maximum structure height44 of the microlenses 21 is between 3 μm and 50 μm, and the dimension 45of the microimages 22 is preferably between 3 μm and 50 μm. With regardto the other configurations of the multilayer body 2, reference is madeto the explanations concerning the multilayer body 1 according to FIG.1a to FIG. 1 f.

FIG. 3 shows a multilayer body 3 constituting a banknote. The multilayerbody 3 has in the region 31 the carrier layer 10, the adhesive layer 11,the decorative layer 12 with the microimages 22 and the transparentlayer 13 with the microlenses 21. In this case, the transparent layer 13can be linked integrally with the carrier layer 10, that is to say thatthe microlenses 21 can also be introduced, preferably embossed, directlyas surface relief into the carrier layer 10 without the use of aseparate layer 13. If a separate layer 13 is applied to the carrierlayer 10, this can advantageously be a radiation-curing lacquer, intowhich the microlenses 21 are embossed by means of an embossing rollerand the lacquer is subsequently cured e.g. using UV radiation. Withregard to the configuration of these layers, reference is made to theabove explanations according to FIG. 1a to FIG. 2. The carrier substrate10 is the carrier substrate of the banknote. In a region 32, the carriersubstrate 10 is embodied in transparent fashion. If the carriersubstrate 10 consists, for example, of a plastic film or of amultilayered laminate of a plurality of plastic layers, then theseplastic layers are embodied such that they are transparent to the humanobserver in the region 32. If a paper substrate is involved, then thecarrier substrate 10 preferably has in the region 32 a window-shapedperforation, which is then covered on both sides by the layers shown inFIG. 3. Outside the region 32, the carrier substrate 10 is preferablyembodied in opaque fashion, that is to say printed with correspondingopaque layers or provided with a correspondingly colored layer. Onto thecarrier substrate 10, a film element comprising the layers 11 and 13 isthen applied onto the front side and a film element comprising thelayers 11, 12 and a layer 15 is applied onto the rear side. The layer 15is an optional protective lacquer layer. The application of these filmelements onto the carrier substrate 10 can be carried out by means ofone of the methods described above, for example by means of transferringthe transfer layer of a transfer film or laminating a laminating filmonto the carrier substrate 10.

As illustrated in FIG. 3, the film elements applied on the carriersubstrate 10 are in this case made particularly thin, since the carriersubstrate here is advantageously used as an additional spacer layer forforming the first optically variable effect and, consequently, the layerthickness of the layer 13 can be chosen to be particularly thin.

Furthermore, it is also possible here for the decorative layer 12 not tobe part of a film element applied onto the carrier substrate 10, ratherfor the decorative layer 12 to be applied directly to the carriersubstrate 10 by means of a printing method.

The advantages already described above are obtained by means of themultilayer body 3.

FIG. 4 shows a multilayer body 4 constituting a modification of themultilayer body 3 according to FIG. 3. The multilayer body 4 comprisesthe carrier substrate 10, the adhesive layers 11, the decorative layer12 with the microimages 22, the transparent layer 13 with themicrolenses 21, and the protective lacquer layer 15. The multilayer body4 is configured like the multilayer body 3 according to FIG. 3 with thedifference that the carrier substrate 10 is embodied in completelytransparent fashion, and that a replication lacquer layer 14 is arrangedabove the transparent layer 13, the refractive index of said replicationlacquer layer differing from the refractive index of the material of thelayer 13. The film element applied to the front side of the carriersubstrate 10 is in this case preferably produced as follows:

The replication lacquer layer 14 is applied to an optional carrier layerand release layer (in the case of a transfer film) and a surface reliefcorresponding to the microlens grid with the microlenses 21 is embossedinto the replication lacquer layer 14. Afterward, said surface relief isfilled with a further lacquer layer, the layer 13, and the furtherlayers, in particular the adhesive layer 11, are then applied.Afterward, the film element is applied onto the carrier substrate 10.The embodiment according to FIG. 4 here has the further advantage thatthe surface structure of the microlenses 21 is not impressed in thefront side, that is to say the upper surface, of the multilayer body andtherefore cannot be reproduced by means of a contact copy. Furthermore,the microlenses are thus protected against mechanical wear, for examplescratches, by the layer 14, such that the durability of the multilayerbody is improved.

FIG. 5 shows a multilayer body 5 constituting a further variation of themultilayer body 3 and of the multilayer body 4 according to FIG. 3 andFIG. 4, respectively. The multilayer body 5 comprises the carriersubstrate 10, the layer 11, the decorative layer 12 with the microimages22, the layer 13 with the microlenses 21, and the layer 14. Themultilayer body 5 is embodied like the multilayer body 4 according toFIG. 4 with the difference that the film element applied onto the frontside of the carrier substrate 10 furthermore has a security element 16,the film element applied onto the underside of the film body has asecurity element 18 and a cover layer 17, and the underside of thecarrier substrate 10 is provided with an imprint 9.

The cover layer 17 is formed by an opaque layer which decouples theoptical effect of the decorative layer 12 and the optical effect of thesecurity element 18 from one another. This layer could also be dispensedwith. The security elements 16 and 18 each consist of one or a pluralityof layers, selected from the group comprising replication lacquer layerwith impressed optically active surface relief, reflection layer, metallayer, color lacquer layer, layer comprising optically active pigments,liquid crystal layer, volume hologram layer and thin-film layer system.In this case, the security element 18 preferably forms a secondoptically variable information item, which differs from the firstoptically variable information item generated in the region 31 by thelayers 13, 15 and 12. Upon viewing from the front side, the opticallyvariable effect generated by the layers 12 and 13 is thus visible in theregion 31 and, upon viewing from the rear side, the optically variableeffect generated by the security element 18 is visible.

The security element 16 can be configured like the security element 18.The security element 16 thus generates a corresponding, preferablyoptically variable impression in a region 33, in which it is provided inthe film element applied with the front side of the carrier substrate10, upon viewing from the front side. Furthermore, the security feature16 is arranged with register accuracy with respect to the securityelement 18. Upon transmitted-light viewing, the security elements 16 and18 complement one another to form a further security element, forexample form mutually complementary representations which combine toform an overall motif, for example, upon transmitted-light viewing. Partof said overall motif is furthermore the imprint 19, which is likewisearranged with register accuracy with respect to the security elements 16and 18. Upon viewing from the front and rear sides in reflected light,preferably the optically variable effect generated by the securityelement 16 is thus manifested in the region 33 and, upon viewing intransmitted light, the “watermark effect” provided by the imprint 19,the security element 16 and the security element 18 is manifested in theregions 31, 33 and 34, said “watermark effect” being determined by theregister-accurate arrangement of the layers of the security elements 16and 18 and of the imprint 19 with respect to one another.

FIG. 6 shows a multilayer body 6 comprising the carrier substrate 10,the adhesive layer 11, the decorative layer 12 with the microimages 22arranged in the region 31, and the transparent layer 13 with themicrolenses 21 arranged in the region 31. The abovementioned layers areembodied like the correspondingly designated layers of the multilayerbody 1 and 2 according to FIG. 1a to FIG. 2 with the difference that, inthe region 31, a window-shaped perforation is additionally provided inthe carrier substrate 10. With regard to the configuration of theselayers, reference is thus made to the explanations above. Furthermore, atranslucent layer 20 is arranged between the decorative layer 12 and thetransparent layer 13. The translucent layer 20 preferably consists of acolored lacquer layer and preferably has a layer thickness of between 1μm and 30 μm.

Furthermore, the decorative layer is embodied such that the transparencyof the decorative layer is different in the image regions and in thebackground regions; by way of example, the background regions areconfigured in fully transparent fashion and the image regions areconfigured in opaque fashion.

What is achieved by the above-described configuration of the multilayerbody 6 is that the optically variable effect generated in the region 31by the layers 12 and 13 is manifested only in transmitted-light viewingand is extinguished in reflected-light viewing by the translucent layer20 and the scattering effect brought about by the latter.

FIG. 7 shows a multilayer body 7 comprising the carrier substrate 10,the adhesive layer 11, the decorative layer 12 and the transparent layer13. These layers are embodied like the correspondingly designated layersaccording to FIG. 1a to FIG. 2, apart from the following differences:

The decorative layer 12 has zones 34 and 33 in the region 31. In thezones 33, the decorative layer 12 is configured in the manner describedabove with respect to FIG. 1 or FIG. 2. In the zones 33, the decorativelayer 12 has a replication lacquer layer having an optically activesurface structure 24, which is provided for generating a furtheroptically variable information item, which differs from the firstoptically variable information item generated in the zones 34.Furthermore, in the zones 33, a lacquer layer 30 is printed onto thesurface of the transparent layer 13. The lacquer layer 30 is a lacquerlayer composed of a material whose refractive index differs from therefractive index of the material of the transparent layer by not morethan 0.3. This has the effect that the optical effect of the microlenses21 is extinguished in the zones 33 for the human observer and only theoptically variable effect generated by the optically active surfacestructure 24 thus becomes visible in the zones 33 for the humanobserver.

A further variant for obtaining the optical effect generated by themultilayer body 7 is explained below with reference to FIG. 8.

FIG. 8 shows a multilayer body 8, comprising the carrier substrate 10,the adhesive layer 11, the decorative layer 12 and the transparent layer13. These layers are constructed like the correspondingly designatedlayers according to FIG. 7 apart from the following differences: insteadof extinguishing the optical effect of the microlenses 21 in the zones33, here firstly the variant is shown where the layer 13 is not providedin the region of the zones 33. The layer 13 is thus fashioned partially,such that the layer 13 with the microlenses 21 is not provided in thezones 33 or in a portion of the zones 33. As a result, the opticallyvariable effect of the optically active surface structures 24 ismanifested particularly brilliantly in these regions 33 because there isno or only partial covering of the optically variable effect by otherlayers. As an alternative thereto, it is possible for the microlenses tobe impressed only partially into the layer 13. As shown in FIG. 8, themicrolenses are thus not impressed in the zones 33 and, by way ofexample, as shown in FIG. 8, are replaced by a planar surface profile ora substantially smooth or planar surface profile without an opticaldistortion function.

Alternatively, investigations have shown that even when dispensing withthe lacquer layer 30 or when implementing one of the two precedingmeasures, the optical impression of the surface structure, particularlywhen a Kinegram® is used, is only slightly blurred by the lenses and itis thus possible, if appropriate, to dispense with the lacquer layer 30or one of the two abovementioned alternatives thereto for obtaining theoptically variable effect outlined in the exemplary embodiment accordingto FIG. 7.

It is furthermore possible that as zones 34 regions having differentlyembodied and/or oriented microimage grid and microstructure grid, asillustrated previously in FIGS. 1b, 1c, 1d, 1e , and zones 33 forgenerating a further optically variable information item are arrangedadjacent to one another alongside one another.

Adjacent in this context means that zones respectively lying alongsideone another have a common boundary line or boundary zone. In order to beable to compensate for the presence of manufacturing tolerances of thepositions of the respective zones, it is possible for zones respectivelylying alongside one another to slightly overlap one another in anoverlap region embodied as a boundary zone, wherein the boundary zone isin each case preferably slightly wider than the maximum manufacturingtolerance, for example has a width of between 10 μm and 5 mm. Boundaryzones can be provided at the entire periphery of a zone or only at partof the periphery, for example only in the region of a boundary line withrespect to an adjacent zone. Such manufacturing tolerances can occur forexample when applying the individual layers in different productionsteps, preferably in a roll-to-roll process for the microimage gridsand/or of the microstructure grids, as a result of which a small offsetin the relative arrangement of the layers with respect to one anothercan arise.

FIG. 9 shows a multilayer body 9 comprising the regions 35, 36 andregions 37 and 38. In the regions 35 to 38, the microimage grid and themicrostructure grid respectively differ from one another, in particularin one of the parameters selected from the group comprising microimagedistance, microstructure distance and orientation of the coordinate axiswhich are spanned by the microstructure grid and the microimage grid.The microimage grid or the microstructure grid can also be identical inindividual regions 35 to 38, but phase-shifted relative to therespective other regions. In the regions 37 and 38, by way of example,the zones 21, 22 and 23 are thus arranged in accordance with amicrostructure grid and a microimage grid, in which the differencebetween the microimage distance and the microstructure distance ispositive in the region 134 and negative in the region 135. By way ofexample, this brings about a contrary movement of the motif manifestedduring tilting in the regions 37 and 38.

In addition, an advantageous combination of zones 34 having opticallyvariable information items with adjacent zones 33 having an opticallyvariable information item contrasting therewith is possible, for exampleas individual motifs within an overall motif, in order that the zones 33can serve as a contrasting optical reference to the optically variableinformation item in the zones 34. By way of example, there can bemovement effects in the regions 35 to 38 and a surrounding region 39without a movement effect or a movement effect in the region 38 with aregion 37 surrounding or adjoining the latter without a movement effect,for example with a hologram and/or with optically variable pigments orelse in each case contrary movement effects in the regions 35 to 38.Contrasting optically variable information items can also be generated,for example, by virtue of the fact that, in one or a plurality ofregions 35 to 38, a microstructure grid is provided above a microimagegrid or above other optically variable motifs and, in other regions 35to 38 directly or indirectly adjacent thereto, the microstructure gridis either extinguished, for example by means of a lacquer layer having asimilar refractive index, or is not provided. It is likewise possible toprovide in the regions 35 to optically variable information itemsadjacent with optically static information items, for examplesingle-colored regions or multicolored, non-optically variable motifs,adjacent to one another.

1. A multilayer body comprising: a transparent first layer including amultiplicity of microlenses spatially arranged to form a microlens gridhaving a grid pitch, said microlenses being impressed in a first surfacearea of the transparent first layer; and a second layer, which isarranged below the first layer and in a fixed position with respect tothe first layer and has a multiplicity of microimages spatially arrangedto form a microimage grid having a grid pitch, each microimage being inan at least partial overlap with one of the microlenses of the microlensgrid for the purpose of generating a first optically variableinformation item, wherein the grid pitches of the microimage grid and ofthe microlens grid in each case in at least one spatial direction areless than 300 μm, and wherein the respective grid pitch of the microlensgrid in a first spatial direction is greater by more than 100%, than therespective dimension of the respective microlens in the first spatialdirection, and wherein flat regions are provided between the microlensessuch that the microlenses do not directly succeed one another. 2.(canceled)
 3. The multilayer body as claimed in claim 1, wherein themaximum structure height of the respective microlens is at least 50%, ofthe dimension of the respective microlens in the first spatialdirection.
 4. The multilayer body as claimed in claim 1, wherein therespective dimension of the microimages in the first spatial directionis more than 100%, of the dimension of the respectively adjacentmicrolens in the first spatial direction.
 5. The multilayer body asclaimed in claim 1, wherein the multilayer body has a carrier substratehaving a layer thickness of more than 6 μm, and wherein the carriersubstrate is embodied in transparent fashion in a second region or has awindow-shaped perforation, wherein the second region covers the firstregion, and wherein the first layer is arranged on the front side of thecarrier substrate and the second layer is arranged on the rear side ofthe carrier substrate.
 6. The multilayer body as claimed in claim 5,wherein the multilayer body is a banknote, and wherein the carriersubstrate forms the carrier substrate of the valuable document and has alayer thickness of 30 μm to 200 μm.
 7. The multilayer body as claimed inclaim 5, wherein the multilayer body has in the first region a thirdlayer, which is arranged below the second layer and which, when themultilayer body is viewed from the rear side, generates a secondoptically variable information item, which is not visible to the humanobserver when viewing the front side of the multilayer body and differsfrom the first optically variable information item.
 8. The multilayerbody as claimed in claim 1, wherein the multilayer body has atranslucent layer arranged between the first layer and the second layer.9. The multilayer body as claimed in claim 8, wherein the multilayerbody has a carrier substrate, which is embodied in transparent fashionin the first region or has a window-shaped perforation.
 10. Themultilayer body as claimed in claim 1, wherein the second layer has atleast one first zone underlying said first surface area, in which themicroimages are provided, and has at least one second zone underlyingsaid first surface area, in which optically active surface structuresfor generating a second optically variable information item areprovided, said second optically variable information item differing fromthe first optically variable information item.
 11. The multilayer bodyas claimed in claim 10, wherein the microlenses are provided in thefirst and second zones.
 12. The multilayer body as claimed in claim 10,wherein, in the at least one second zone, a lacquer layer is printed,onto the first layer, the lacquer layer having a refractive index andthe first layer having a refractive index, the refractive index of saidlacquer layer differing from the refractive index of the first layer byless than 0.3.
 13. The multilayer body as claimed in claim 10, whereinat least one second zone has a smallest dimension of more than 300 μmand is shaped in patterned fashion for generating an information item inaddition to the first and second optically variable information items.14. The multilayer body as claimed in claim 10, wherein the firstsurface area of the transparent first layer is subdivided into amultiplicity of first and second zones, and wherein the first and secondzones are spatially arranged to form a grid having a grid pitch of lessthan 300 μm in at least one spatial direction.
 15. The multilayer bodyas claimed in claim 1, wherein the microimages are in each case formedby one or a plurality of image regions surrounded by a backgroundregion.
 16. The multilayer body as claimed in claim 15, wherein the oneor the plurality of image regions is or are opaque and the backgroundregion is transparent, or vice versa.
 17. The multilayer body as claimedin claim 15, wherein the one or the plurality of image regions, on theone hand, and the background region, on the other hand, have differentreflection properties.
 18. The multilayer body as claimed in claim 15,wherein the second layer has a metallic layer, a colored lacquer layerand/or a photoresist layer which is provided in the image regions and isnot provided in the background region, or vice versa.
 19. The multilayerbody as claimed in claim 15, wherein the image regions and thebackground region are covered with different optically variableelements.
 20. The multilayer body as claimed in claim 19, wherein thesecond layer has a replication lacquer layer having a surface reliefimpressed into a surface of the replication lacquer layer.
 21. Themultilayer body as claimed in claim 15, wherein the one or the pluralityof image regions and the background region have different polarizationproperties.
 22. The multilayer body as claimed in claim 15, wherein thecolor, the reflection properties and/or the absorption properties of thesecond layer are/is varied within the image regions.
 23. The multilayerbody as claimed in claim 1, wherein the microlens grid is arranged in amanner rotated by 45° relative to the longitudinal axis of themultilayer body.
 24. The multilayer body as claimed in claim 23, whereinthe microlens grid is a one-dimensional microlens grid and the focalpoint lines of the microlenses are arranged in a manner rotated by 45°relative to the longitudinal axis of the multilayer body.
 25. Themultilayer body as claimed in claim 1, wherein the microimages are ineach case applied on a curved surface.
 26. The multilayer body asclaimed in claim 1, wherein the microlens grid and/or the microimagegrid are/is a two-dimensional microlens grid and/or microimage grid andin each case two or more microlenses and/or microimages succeed oneanother in a first spatial direction and in a second spatial directionwith a respective grid pitch of between 5 μm and 150 μm.
 27. Themultilayer body as claimed in claim 1, wherein the microlens grid and/orthe microimage grid are/is a one-dimensional microlens grid and/ormicroimage grid and in each case two or more microlenses and/ormicroimages succeed one another in a first spatial direction with arespective grid pitch of between 5 μm and 300 μm.
 28. The multilayerbody as claimed in claim 1, wherein the grid pitches of the microimagegrid and microlens grid differ from one another in each case foradjacent microimages and microlenses by between 0.5 and 5%.
 29. Themultilayer body as claimed in claim 1, wherein the microimage grid andthe microlens grid are arranged in a manner rotated by between 0.50 and500 relative to one another.
 30. The multilayer body as claimed in claim1, wherein, in the first region, the grid pitch of the microlens gridand/or of the microimage grid and/or the rotation of the microimage gridand of the microlens grid relative to one another are/is variedcontinuously in accordance with a parameter variation function in atleast one spatial direction.
 31. The multilayer body as claimed in claim1, wherein the microimage grid has in the first region at least twomicroimages which differ from one another.
 32. The multilayer body asclaimed in claim 1, wherein, in the second region, the form and/or thecolor of the microimage are/is varied continuously in accordance with atransformation function.
 33. The multilayer body as claimed in claim 1,wherein, in a first partial region of the first region, the grid pitchof the microlens grid, the grid pitch of the microimage grid and/or therotation of the microimage grid and of the microlens grid with respectto one another differs from the grid pitch of the microlens grid, thegrid pitch of the microimage grid and/or the rotation of the microimagegrid and of the microlens grid relative to one another in a secondpartial region of the first region.
 34. A multilayer body comprising: atransparent first layer including a multiplicity of microlensesspatially arranged to form a microlens grid having a grid pitch, saidmicrolenses being impressed in a first surface area of the transparentlayer; and a second layer, which is arranged below the first layer andin a fixed position with respect to the first layer and has amultiplicity of microimages spatially arranged to form a microimage gridhaving a grid pitch, each microimage being in an at least partialoverlap with one of the microlenses of the microlens grid for generatinga first optically variable information item, wherein the grid pitches ofthe microimage grid and of the microlens grid in each case in at leastone spatial direction are less than 300 μm, and wherein the microimagesare in each case formed by one or a plurality of image regionssurrounded by a background region, the image regions and the backgroundregion being coplanar and adjacent to each other, and wherein thebackground region is formed by at least one of: a metallic layer; acolored lacquer layer; and a photoresist layer, and wherein none of themetallic layer, the colored lacquer layer or the photoresist layer isprovided in the plurality of image regions
 35. A multilayer bodycomprising: a transparent first layer including a multiplicity ofmicrolenses spatially arranged to form a microlens grid having a gridpitch, said microlenses being impressed in a first surface area of thetransparent layer; and a second layer, which is arranged below the firstlayer and in a fixed position with respect to the first layer and has amultiplicity of microimages spatially arranged to form a microimage gridhaving a grid pitch, each microimage being in an at least partialoverlap with one of the microlenses of the microlens grid for generatinga first optically variable information item, wherein the grid pitches ofthe microimage grid and of the microlens grid in each case in at leastone spatial direction are less than 300 μm, and wherein the microimagesare in each case formed by one or a plurality of image regionssurrounded by a background region, the image regions and the backgroundregion being coplanar and adjacent to each other, and wherein the imageregions are formed by at least one of: a metallic layer; a coloredlacquer layer; and a photoresist layer, and wherein none of the metalliclayer, the colored lacquer layer or the photoresist layer is provided inthe background region.